Inhibition of ROCK1 kinase modulates both tumor cells and stromal fibroblasts in pancreatic cancer

Long noncoding RNAs and HPV-related cervical cancer: Uncovering molecular mechanisms and clinical applications

Cervical cancer (CC) is the primary cause of cancer-related mortality among women in developing countries and is the most prevalent disease linked to human papillomavirus (HPV). Over 70 % of CC cases result from persistent infections with high-risk HPV types. The virus typically targets the mucocutaneous epithelium, generating viral particles in mature epithelial cells, which leads to disruptions in normal cell-cycle regulation and promotes uncontrolled cellular proliferation. This unchecked cell division results in the accumulation of genetic damage, contributing to the pathogenesis of CC. While HPV infection is a key etiological factor, the disease's progression also necessitates the involvement of genetic and epigenetic influences. One of the epigenetic regulators, long noncoding RNAs (lncRNAs), are characterized by transcripts exceeding 200 nucleotides. These molecules play crucial roles in various cellular processes, including transcription regulation, RNA metaboli35 per 100,000sm, and apoptosis. Investigating the specific roles of lncRNAs in modulating gene expression related to the oncogenic mechanisms of CC, particularly in the context of high-risk HPV infections, may provide valuable insights for diagnostic and therapeutic advancements. Herein, we first review key molecular mechanisms by which lncRNAs interfere with CC-related HPV development. Then, diagnostic, prognostic, and therapeutic potentials of these lncRNA molecules will be highlighted in depth. The focus of this article is on the role of lncRNAs associated with HPV-related CC, emphasizing the investigation of signaling pathways and their underlying molecular mechanisms. Furthermore, we explore the therapeutic potential and diagnostic relevance of the most significant lncRNAs in the context of CC, thereby highlighting their importance in advancing treatment strategies and improving patient outcomes.

Cancer associated fibroblasts in cancer development and therapy

Cancer-associated fibroblasts (CAFs) are key players in cancer development and therapy, and they exhibit multifaceted roles in the tumor microenvironment (TME). From their diverse cellular origins, CAFs undergo phenotypic and functional transformation upon interacting with tumor cells and their presence can adversely influence treatment outcomes and the severity of the cancer. Emerging evidence from single-cell RNA sequencing (scRNA-seq) studies have highlighted the heterogeneity and plasticity of CAFs, with subtypes identifiable through distinct gene expression profiles and functional properties. CAFs influence cancer development through multiple mechanisms, including regulation of extracellular matrix (ECM) remodeling, direct promotion of tumor growth through provision of metabolic support, promoting epithelial-mesenchymal transition (EMT) to enhance cancer invasiveness and growth, as well as stimulating cancer stem cell properties within the tumor. Moreover, CAFs can induce an immunosuppressive TME and contribute to therapeutic resistance. In this review, we summarize the fundamental knowledge and recent advances regarding CAFs, focusing on their sophisticated roles in cancer development and potential as therapeutic targets. We discuss various strategies to target CAFs, including ECM modulation, direct elimination, interruption of CAF-TME crosstalk, and CAF normalization, as approaches to developing more effective treatments. An improved understanding of the complex interplay between CAFs and TME is crucial for developing new and effective targeted therapies for cancer.

Mechanical forces in the tumor microenvironment: roles, pathways, and therapeutic approaches

Tumors often exhibit greater stiffness compared to normal tissues, primarily due to increased deposition within the tumor stroma. Collagen, proteoglycans, laminin, and fibronectin are key components of the extracellular matrix (ECM), interacting to facilitate ECM assembly. Enhanced fiber density and cross-linking within the ECM result in elevated matrix stiffness and interstitial fluid pressure, subjecting tumors to significant physical stress during growth. This mechanical stress is transduced intracellularly via integrins, the Rho signaling pathway, and the Hippo signaling pathway, thereby promoting tumor invasion. Additionally, mechanical pressure fosters glycolysis in tumor cells, boosting energy production to support metastasis. Mechanical cues also regulate macrophage polarization, maintaining an inflammatory microenvironment conducive to tumor survival. In summary, mechanical signals within tumors play a crucial role in tumor growth and invasion. Understanding these signals and their involvement in tumor progression is essential for advancing our knowledge of tumor biology and enhancing therapeutic approaches.

Identifying key genes in cancer networks using persistent homology

Identifying driver genes is crucial for understanding oncogenesis and developing targeted cancer therapies. Driver discovery methods using protein or pathway networks rely on traditional network science measures, focusing on nodes, edges, or community metrics. These methods can overlook the high-dimensional interactions that cancer genes have within cancer networks. This study presents a novel method using Persistent Homology to analyze the role of driver genes in higher-order structures within Cancer Consensus Networks derived from main cellular pathways. We integrate mutation data from six cancer types and three biological functions: DNA Repair, Chromatin Organization, and Programmed Cell Death. We systematically evaluated the impact of gene removal on topological voids ([Formula: see text] structures) within the Cancer Consensus Networks. Our results reveal that only known driver genes and cancer-associated genes influence these structures, while passenger genes do not. Although centrality measures alone proved insufficient to fully characterize impact genes, combining higher-order topological analysis with traditional network metrics can improve the precision of distinguishing between drivers and passengers. This work shows that cancer genes play an important role in higher-order structures, going beyond pairwise measures, and provides an approach to distinguish drivers and cancer-associated genes from passenger genes.

Unveiling the resistance to therapies in pancreatic ductal adenocarcinoma

Despite the ongoing advances in interventional strategies (surgery, chemotherapy, radiotherapy, and immunotherapy) for managing pancreatic ductal adenocarcinoma (PDAC), the development of therapy refractory phenotypes remains a significant challenge. Resistance to various therapeutic modalities in PDAC emanates from a combination of inherent and acquired factors and is attributable to cancer cell-intrinsic and -extrinsic mechanisms. The critical determinants of therapy resistance include oncogenic signaling and epigenetic modifications that drive cancer cell stemness and metabolic adaptations, CAF-mediated stromagenesis that results in ECM deposition altered mechanotransduction, and secretome and immune evasion. We reviewed the current understanding of these multifaceted mechanisms operating in the PDAC microenvironment, influencing the response to chemotherapy, radiotherapy, and immunotherapy regimens. We then describe how the lessons learned from these studies can guide us to discover novel therapeutic regimens to prevent, delay, or revert resistance and achieve durable clinical responses.

ROCK1 regulates glycolysis in pancreatic cancer via the c-MYC/PFKFB3 pathway

BACKGROUND

Dysregulation of Rho-associated coiled coil-containing protein kinases (ROCKs) is involved in the metastasis and progression of various malignant tumors. However, how one of the isomers, ROCK1, regulates glycolysis in tumor cells is incompletely understood. Here, we attempted to elucidate how ROCK1 influences pancreatic cancer (PC) progression by regulating glycolytic activity.

METHODS

The biological function of ROCK1 was analyzed in vitro by establishing a silenced cell model. Coimmunoprecipitation confirmed the direct binding between ROCK1 and c-MYC, and a luciferase reporter assay revealed the binding of c-MYC to the promoter of the PFKFB3 gene. These results were verified in animal experiments.

RESULTS

ROCK1 was highly expressed in PC tissues and enriched in the cytoplasm, and its high expression was associated with a poor prognosis. Silencing ROCK1 inhibited the proliferation and migration of PC cells and promoted their apoptosis. Mechanistically, ROCK1 directly interacted with c-MYC, promoted its phosphorylation (Ser 62) and suppressed its degradation, thereby increasing the transcription of the key glycolysis regulatory factor PFKFB3, enhancing glycolytic activity and promoting PC growth. Silencing ROCK1 increased gemcitabine (GEM) sensitivity in vivo and in vitro.

CONCLUSIONS

ROCK1 promotes glycolytic activity in PC cells and promotes PC tumor growth through the c-MYC/PFKFB3 signaling pathway. ROCK1 knockdown can inhibit PC tumor growth in vivo and increase the GEM sensitivity of PC tumors, providing a crucial clinical therapeutic strategy for PC.

Development of Novel ROCK Inhibitors via 3D-QSAR and Molecular Docking Studies: A Framework for Multi-Target Drug Design

Background/Objectives: Alterations in the actin cytoskeleton correlates to tumor progression and affect critical cellular processes such as adhesion, migration and invasion. Rho-associated coiled-coil-containing protein kinases (ROCK1 and ROCK2), important regulators of the actin cytoskeleton, are frequently overexpressed in various malignancies. The aim of this study was therefore to identify the key structural features of ROCK1/ROCK2 inhibitors using computer-aided drug design (CADD) approaches. In addition, new developed ROCK inhibitors provided a significant framework for the development of multitarget therapeutics-ROCK/HDAC (histone deacetylases) multitarget inhibitors. Methods: 3D-QSAR (Quantitative structure-activity relationship study) and molecular docking study were employed in order to identify key structural features that positively correlate with ROCK inhibition. MDA-MB-231, HCC1937, Panc-1 and Mia PaCa-2 cells were used for evaluation of anticancer properties of synthesized compounds. Results: C-19 showed potent anti-cancer properties, especially enhancement of apoptosis and cell cycle modulation in pancreatic cancer cell lines. In addition, C-19 and C-22 showed potent anti-migratory and anti-invasive effects comparable to the well-known ROCK inhibitor fasudil. Conclusions: In light of the results of this study, we propose a novel multi-target approach focusing on developing dual HDAC/ROCK inhibitors based on the structure of both C-19 and C-22, exploiting the synergistic potential of these two signaling pathways to improve therapeutic efficacy in metastatic tumors. Our results emphasize the potential of multi-target ROCK inhibitors as a basis for future cancer therapies.

Non-Muscle Myosin II A: Friend or Foe in Cancer?

Non-muscle myosin IIA (NM IIA) is a motor protein that belongs to the myosin II family. The myosin heavy chain 9 (MYH9) gene encodes the heavy chain of NM IIA. NM IIA is a hexamer and contains three pairs of peptides, which include the dimer of heavy chains, essential light chains, and regulatory light chains. NM IIA is a part of the actomyosin complex that generates mechanical force and tension to carry out essential cellular functions, including adhesion, cytokinesis, migration, and the maintenance of cell shape and polarity. These functions are regulated via light and heavy chain phosphorylation at different amino acid residues. Apart from physiological functions, NM IIA is also linked to the development of cancer and genetic and neurological disorders. MYH9 gene mutations result in the development of several autosomal dominant disorders, such as May-Hegglin anomaly (MHA) and Epstein syndrome (EPS). Multiple studies have reported NM IIA as a tumor suppressor in melanoma and head and neck squamous cell carcinoma; however, studies also indicate that NM IIA is a critical player in promoting tumorigenesis, chemoradiotherapy resistance, and stemness. The ROCK-NM IIA pathway regulates cellular movement and shape via the control of cytoskeletal dynamics. In addition, the ROCK-NM IIA pathway is dysregulated in various solid tumors and leukemia. Currently, there are very few compounds targeting NM IIA, and most of these compounds are still being studied in preclinical models. This review provides comprehensive evidence highlighting the dual role of NM IIA in multiple cancer types and summarizes the signaling networks involved in tumorigenesis. Furthermore, we also discuss the role of NM IIA as a potential therapeutic target with a focus on the ROCK-NM IIA pathway.

Targeting endocytosis to sensitize cancer cells to programmed cell death

Evading programmed cell death (PCD) is a hallmark of cancer that allows tumor cells to survive and proliferate unchecked. Endocytosis, the process by which cells internalize extracellular materials, has emerged as a key regulator of cell death pathways in cancer. Many tumor types exhibit dysregulated endocytic dynamics that fuel their metabolic demands, promote resistance to cytotoxic therapies, and facilitate immune evasion. This review examines the roles of endocytosis in apoptotic resistance and immune escape mechanisms utilized by cancer cells. We highlight how inhibiting endocytosis can sensitize malignant cells to therapeutic agents and restore susceptibility to PCD. Strategies to modulate endocytosis for enhanced cancer treatment are discussed, including targeting endocytic regulatory proteins, altering membrane biophysical properties, and inhibiting Rho-associated kinases. While promising, challenges remain regarding the specificity and selectivity of endocytosis-targeting agents. Nonetheless, harnessing endocytic pathways represents an attractive approach to overcome apoptotic resistance and could yield more effective therapies by rendering cancer cells vulnerable to PCD. Understanding the interplay between endocytosis and PCD regulation is crucial for developing novel anticancer strategies that selectively induce tumor cell death.

Focus on Pancreatic Cancer Microenvironment

Pancreatic ductal adenocarcinoma remains one of the most lethal solid tumors due to its local aggressiveness and metastatic potential, with a 5-year survival rate of only 13%. A robust connection between pancreatic cancer microenvironment and tumor progression exists, as well as resistance to current anticancer treatments. Pancreatic cancer has a complex tumor microenvironment, characterized by an intricate crosstalk between cancer cells, cancer-associated fibroblasts and immune cells. The complex composition of the tumor microenvironment is also reflected in the diversity of its acellular components, such as the extracellular matrix, cytokines, growth factors and secreted ligands involved in signaling pathways. Desmoplasia, the hallmark of the pancreatic cancer microenvironment, contributes by creating a dense and hypoxic environment that promotes further tumorigenesis, provides innate systemic resistance and suppresses anti-tumor immune invasion. We discuss the complex crosstalk among tumor microenvironment components and explore therapeutic strategies and opportunities in pancreatic cancer research. Better understanding of the tumor microenvironment and its influence on pancreatic cancer progression could lead to potential novel therapeutic options, such as integration of immunotherapy and cytokine-targeted treatments.

LINC00645 inhibits renal cell carcinoma progression by interacting with HNRNPA2B1 to regulate the ROCK1 mRNA stability

The lncRNA plays an important role in tumorigenesis and the progression of renal cell carcinoma (RCC). LINC00645 is one of the most different expressed lncRNA between RCC and normal renal tissue. However, the regulatory mechanism of LINC00645 in RCC remains unknown. Our results indicated that LINC00645 inhibited RCC proliferation, migration, and invasion. Mechanistically, HNRNPA2B1 directly bound to ROCK1 mRNA and strengthened its stability. LINC00645 competitively bound to the RRM1 domain, which is responsible for interacting with ROCK1 mRNA, reducing ROCK1 mRNA level by affecting posttranscriptional destabilization. The expression of LINC00645 was significantly reduced in RCC cells, significantly upregulating ROCK1 by abolishing the interaction with HNRNPA2B1, finally promoting RCC proliferation, migration, and invasion. Moreover, RCC cells with lower LINC00645 expression were more sensitive to the ROCK1 inhibitor Y-27632. Our study indicates that decreased expression of LINC00645 promotes the RCC progression via HNRNPA2B1/ROCK1 axis, providing a promising treatment strategy for RCC patients with decreased LINC00645 expression.

Recent advances in the development of Rho kinase inhibitors (2015-2021)

Rho-associated coiled-coil kinases (ROCKs) are key downstream effectors of small GTPases. ROCK plays a central role in diverse cellular events with accumulating evidence supporting the concept that ROCK is important in tumor development and progression. Numerous ROCK inhibitors have been investigated for their therapeutic potential in the treatment of cancers. In this article, we review recent research progress on ROCK inhibitors, especially those with potential for the treatment of cancers, reported in the literature from 2015 to 2021. Most ROCK inhibitors show potent in vitro and in vivo antitumor activities and have potential in the treatment of cancers.

Cancer-associated fibroblasts: Mediators of head and neck tumor microenvironment remodeling

Cancer-associated fibroblasts (CAFs) are involved in critical aspects of head and neck squamous cell carcinoma (HNSCC) pathogenesis, such as the formation of a tumor-permissive extracellular matrix structure, angiogenesis, or immune and metabolic reprogramming of the tumor microenvironment (TME), with implications for metastasis and resistance to radiotherapy and chemotherapy. The pleiotropic effect of CAFs in TME is likely to reflect the heterogeneity and plasticity of their population, with context-dependent effects on carcinogenesis. The specific properties of CAFs provide many targetable molecules that could play an important role in the future therapy of HNSCC. In this review article, we will focus on the role of CAFs in the TME of HNSCC tumors. We will also discuss clinically relevant agents targeting CAFs, their signals, and signaling pathways, which are activated by CAFs in cancer cells, with the potential for repurposing for HNSCC therapy.

Fibroblasts in cancer: Unity in heterogeneity

Tumor cells do not exist in isolation in vivo, and carcinogenesis depends on the surrounding tumor microenvironment (TME), composed of a myriad of cell types and biophysical and biochemical components. Fibroblasts are integral in maintaining tissue homeostasis. However, even before a tumor develops, pro-tumorigenic fibroblasts in close proximity can provide the fertile 'soil' to the cancer 'seed' and are known as cancer-associated fibroblasts (CAFs). In response to intrinsic and extrinsic stressors, CAFs reorganize the TME enabling metastasis, therapeutic resistance, dormancy and reactivation by secreting cellular and acellular factors. In this review, we summarize the recent discoveries on CAF-mediated cancer progression with a particular focus on fibroblast heterogeneity and plasticity.

MicroRNA-148a Controls Epidermal and Hair Follicle Stem/Progenitor Cells by Modulating the Activities of ROCK1 and ELF5

Skin and hair development is regulated by complex programs of gene activation and silencing and microRNA-dependent modulation of gene expression to maintain normal skin and hair follicle development, homeostasis, and cycling. In this study, we show that miR-148a, through its gene targets, plays an important role in regulating skin homeostasis and hair follicle cycling. RNA and protein analysis of miR-148a and its gene targets were analyzed using a combination of in vitro and in vivo experiments. We show that the expression of miR-148a markedly increases during telogen (bulge and hair germ stem cell compartments). Administration of antisense miR-148a inhibitor into mouse skin during the telogen phases of the postnatal hair cycle results in accelerated anagen development and altered stem cell activity in the skin. We also show that miR-148a can regulate colony-forming abilities of hair follicle bulge stem cells as well as control keratinocyte proliferation/differentiation processes. RNA and protein analysis revealed that miR-148a may control these processes by regulating the expression of Rock1 and Elf5 in vitro and in vivo. These data provide an important foundation for further analyses of miR-148a as a crucial regulator of these genes target in the skin and hair follicles and its importance in maintaining stem/progenitor cell functions during normal tissue homeostasis and regeneration.

Preclinical to clinical utility of ROCK inhibitors in cancer

ROCK belongs to the AGC family of Ser/Thr protein kinases that are involved in many cellular processes. ROCK-driven actomyosin contractility regulates cytoskeletal dynamics underpinning cell migration, proliferation, and survival in many cancer types. ROCK1/2 play key protumorigenic roles in several subtypes and stages of cancer development. Therefore, successfully targeting ROCK and its downstream effectors presents an interesting avenue for cancer treatment. Because local use of ROCK inhibitors will reduce the side effects of systemic administration, we propose different therapeutic strategies and latest-generation ROCK inhibitors for use in the clinic.

Identification and Validation of the Anoikis-Related Gene Signature as a Novel Prognostic Model for Cervical Squamous Cell Carcinoma, Endocervical Adenocarcinoma, and Revelation Immune Infiltration

Background and Objectives: Cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) are malignant disorders with adverse prognoses for advanced patients. Anoikis, which is involved in tumor metastasis, facilitates the survival and separation of tumor cells from their initial site. Unfortunately, it is rarely studied, and in the literature, studies have only addressed the prognosis character of anoikis for patients with CESC. Materials and Methods: We utilized anoikis-related genes (ANRGs) to construct a prognostic signature in CESC patients that were selected from the Genecards and Harmonizome portals. Furthermore, we revealed the underlying clinical value of this signature for clinical maneuvers by providing clinical specialists with an innovative nomogram on the basis of ANRGs. Finally, we investigated the immune microenvironment and drug sensitivity in different risk groups. Results: We screened six genes from fifty-eight anoikis-related differentially expressed genes in the TCGA-CESC cohort, and we constructed a prognostic signature. Then, we built a nomogram combined with CESC clinicopathological traits and risk scores, which demonstrated that this model may improve the prognosis of CESC patients in clinical therapy. Next, the prognostic risk scores were confirmed to be an independent prognostic indicator. Additionally, we programmed a series of analyses, which included immune infiltration analysis, therapy-related analysis, and GSVA enrichment analysis, to identify the functions and mechanisms of the prognostic models during the progression of cancer in CESC patients. Finally, we performed quantitative reverse transcription polymerase chain reaction (qRT-PCR) to verify the six ANRGs. Conclusions: The present discovery verified that the predictive 6-anoikis-related gene (6-ANRG) signature and nomogram serve as imperative factors that might notably impact a CESC patient's prognosis, and they may be able to provide new clinical evidence to assume the role of underlying biological biomarkers and thus become indispensable indicators for prospective diagnoses and advancing therapy.

A primer on cancer-associated fibroblast mechanics and immunosuppressive ability

Cancer-associated fibroblasts (CAFs) are a major point of interest in modern oncology. Their interest resides in their ability to favor tumor growth without carrying genetic mutations. From a translational standpoint, they are potential therapeutic targets, particularly for hard-to-treat solid cancers. CAFs can be defined as non-tumor cells within the tumor microenvironment that have the morphological traits of fibroblasts, are negative for lineage-specific markers (e.g., leukocyte, endothelium), and enhance tumor progression in a multi-pronged manner. Two often-mentioned aspects of CAF biology are their ability to alter the mechanics and architecture of the tumor microenvironment, and also to drive local immunosuppression. These two aspects are the specific focus of this work, which also contains a brief summary of novel therapeutic interventions under study to normalize or eliminate CAFs from the tumor microenvironment.

The role of RAS oncogenes in controlling epithelial mechanics

Mutations in RAS are key oncogenic drivers and therapeutic targets. Oncogenic Ras proteins activate a network of downstream signalling pathways, including extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K), promoting cell proliferation and survival. However, there is increasing evidence that RAS oncogenes also alter the mechanical properties of both individual malignant cells and transformed tissues. Here we discuss the role of oncogenic RAS in controlling mechanical cell phenotypes and how these mechanical changes promote oncogenic transformation in single cells and tissues. RAS activation alters actin organisation and actomyosin contractility. These changes alter cell rheology and impact mechanosensing through changes in substrate adhesion and YAP/TAZ-dependent mechanotransduction. We then discuss how these changes play out in cell collectives and epithelial tissues by driving large-scale tissue deformations and the expansion of malignant cells. Uncovering how RAS oncogenes alter cell mechanics will lead to a better understanding of the morphogenetic processes that underlie tumour formation in RAS-mutant cancers.

Culprits of PDAC resistance to gemcitabine and immune checkpoint inhibitor: Tumour microenvironment components

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal cancer with a dismal five-year survival rate of 11%. Despite remarkable advancements in cancer therapeutics, PDAC patients rarely benefit from it due to insurmountable treatment resistance. Notably, PDAC is pathologically characterized by an extensive desmoplastic reaction and an extremely immunosuppressive tumour microenvironment (TME). The PDAC TME consists of cell components (e.g., tumour, immune and stromal cells) and noncellular components (e.g., extracellular matrix), exhibiting high complexity and their interplay resulting in resistance to chemotherapeutics and immune checkpoint inhibitors. In our review, we shed light on how crosstalk of complex environmental components modulates PDAC drug resistance, and we summarize related clinical trials. Moreover, we extend our discussion on TME exploration and exosome analysis, providing new insights into clinical applications, including personalized medicine, disease monitoring and drug carriers.

Rho-associated kinase1 promotes laryngeal squamous cell carcinoma tumorigenesis and progression via the FAK signaling pathway

Laryngeal squamous cell carcinoma (LSCC) is one of the most common head and neck squamous cell carcinomas (HNSCC). Rho-associated kinase1 (ROCK1) is considered to promote progression of numerous cancers, however, its role in LSCC is still unknown. Here, the expression level of ROCK1 is higher in LSCC tissues than non-tumor tissues, and the expression level of ROCK1 is positively correlated with advanced stage and poor survival prognosis. ROCK1 knockdown in TU686 and TU212 cells dramatically inhibits cellular proliferation, migration and invasion. Whereas the overexpression of ROCK1 reversed these changes. FAK signaling pathway plays an essential role in promoting LSCC progression. Inhibiting FAK activity with TAE226 observably impairs the tumor-promoting effects. In conclusion, ROCK1 promotes LSCC tumorigenesis and progression via the FAK signaling pathway, targeting the ROCK1 molecule may represent potential targets for clinical LSCC treatment.

Rigid Tissue Increases Cytoplasmic pYAP Expression in Pre-Malignant Stage of Lung Squamous Cell Carcinoma (SCC) In Vivo

Increased tissue rigidity is able to activate the Hippo signaling pathway, leading to YAP inactivation by phosphorylation and translocation into the cytoplasm. Accumulating evidence suggests that cytoplasmic pYAP serves as a tumor suppressor and could be a prognostic biomarker for several solid cancers. However, the relationship between tissue rigidity and cytoplasmic pYAP expression in the early stage of lung squamous cell carcinoma (SCC) remains elusive; this was determined in this study by using a mouse model. Female BALB/c mice were assigned into two groups (n = 6; the vehicle (VC) and the pre-malignant (PM) group, which received 70% acetone and 0.04 M N-nitroso-tris-chloroethylurea (NTCU) for 15 weeks, respectively. In this study, the formation of hyperplasia and metaplasia lesions was found in the PM group, indicating the pre-malignant stage of lung SCC. The pre-malignant tissue appeared to be more rigid as characterized by significantly higher (p < 0.05) epithelium thickness, proliferative activity, and collagen content than the VC group. The PM group also had a significantly higher (p < 0.05) cytoplasmic pYAP protein expression than the VC group. In conclusion, increased tissue rigidity may contribute to the upregulation of cytoplasmic pYAP expression, which may act as a tumor suppressor in the early stage of lung SCC.

Prenatal diagnosis and genetic counseling of a paternally inherited microduplication 18q11.1 to 18q11.2 in a chinese family

BACKGROUND

Copy number variants are a substantial source of pathogenic or normal genome variations. Chromosomal imbalances of several megabasepair are normally harmful for the affected person. Still, rarely reported are so-called "unbalanced chromosome abnormalities" (UBCAs), which are either losses or gains or equally large genomic regions, but the carrier is only minimally clinically affected even no clinically affected. The knowledge of such UBCAs is imperative also in noninvasive prenatal testing (NIPT) or chromosomal microarray analysis.

CASE PRESENTATION

A paternally inherited dup(18)(q11.1q11.2) was identified in a over two generations in a Chinese family. The affected region encompasses 25 genes, among which GATA6 is expressed in fetal endothelial cells and mesodermal cells. GATA6 duplications and /or mutations have been seen in cases with congenital heart disease but also non-affected individuals, suggesting incomplete penetrance and variable expressivity.

CONCLUSIONS

Duplications in the region of chromosome 18q11 have been rare reported previously in clinically healthy persons. Here a further family with an UBCA in 18q11 is added to the literature, suggesting a careful genetic counselling in prenatal diagnosis.

Chrysin-Induced G Protein-Coupled Estrogen Receptor Activation Suppresses Pancreatic Cancer

Pancreatic cancer (PC) has a high mortality rate due to its poor prognosis and the possibility of surgical resection in patients with the disease. Importantly, adjuvant chemotherapy is necessary to improve PC prognosis. Chrysin, a natural product with anti-inflammatory, antioxidant, and anticancer properties, has been studied for several years. Our previous study demonstrated that chrysin induced G protein-coupled estrogen receptor (GPER) expression and regulated its activity in breast cancer. Herein, we investigated whether chrysin-induced GPER activation suppresses PC progression in MIA PaCa-2 cells and a xenograft model. To determine its mechanism of action, cytotoxicity and clonogenic assays, a FACS analysis, and Western blotting were performed. Furthermore, the delay in tumor growth was evaluated in the MIA PaCa-2-derived xenograft model. Tumor tissues were investigated by Western blotting, immunohistochemistry, and a proteomic analysis. Chrysin caused cell cycle arrest and significantly decreased cell viability. Following co-treatment with chrysin and 17β-estradiol, the inhibitory effect of chrysin on cell proliferation was enhanced. In the xenograft model, chrysin and G1 (a GPER agonist) significantly delayed tumor growth and reduced both Ki-67 (a proliferation marker) and c-Myc expressions in tumor tissues. The proteomic analysis of tumor tissues identified that rho-associated coiled-coil containing protein kinase 1 (ROCK1), transgelin 2 (TAGLN2), and FCH and Mu domain containing endocytic adaptor 2 (FCHO2) levels were significantly reduced in chrysin-treated tumor tissues. High ROCK1, TAGLN2, and FCHO2 expressions were indicative of low overall PC survival as found using the Kaplan-Meier plotter. In conclusion, our results suggest that chrysin suppresses PC progression through the activation of GPER and reductions in ROCK1, TAGLN2, and FCHO2 expressions.

Cancer-associated fibroblasts in pancreatic cancer: new subtypes, new markers, new targets

Cancer-associated fibroblasts (CAFs) have conflicting roles in the suppression and promotion of cancer. Current research focuses on targeting the undesirable properties of CAFs, while attempting to maintain tumour-suppressive roles. CAFs have been widely associated with primary or secondary therapeutic resistance, and strategies to modify CAF function have therefore largely focussed on their combination with existing therapies. Despite significant progress in preclinical studies, clinical translation of CAF targeted therapies has achieved limited success. Here we will review our emerging understanding of heterogeneous CAF populations in tumour biology and use examples from pancreatic ductal adenocarcinoma to explore why successful clinical targeting of protumourigenic CAF functions remains elusive. Single-cell technologies have allowed the identification of CAF subtypes with a differential impact on prognosis and response to therapy, but currently without clear consensus. Identification and pharmacological targeting of CAF subtypes associated with immunotherapy response offers new hope to expand clinical options for pancreatic cancer. Various CAF subtype markers may represent biomarkers for patient stratification, to obtain enhanced response with existing and emerging combinatorial therapeutic strategies. Thus, CAF subtyping is the next frontier in understanding and exploiting the tumour microenvironment for therapeutic benefit. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Disruption of pancreatic stellate cell myofibroblast phenotype promotes pancreatic tumor invasion

In pancreatic ductal adenocarcinoma (PDAC), differentiation of pancreatic stellate cells (PSCs) into myofibroblast-like cancer-associated fibroblasts (CAFs) can both promote and suppress tumor progression. Here, we show that the Rho effector protein kinase N2 (PKN2) is critical for PSC myofibroblast differentiation. Loss of PKN2 is associated with reduced PSC proliferation, contractility, and alpha-smooth muscle actin (α-SMA) stress fibers. In spheroid co-cultures with PDAC cells, loss of PKN2 prevents PSC invasion but, counter-intuitively, promotes invasive cancer cell outgrowth. PKN2 deletion induces a myofibroblast to inflammatory CAF switch in the PSC matrisome signature both in vitro and in vivo. Further, deletion of PKN2 in the pancreatic stroma induces more locally invasive, orthotopic pancreatic tumors. Finally, we demonstrate that a PKN2KO matrisome signature predicts poor outcome in pancreatic and other solid human cancers. Our data indicate that suppressing PSC myofibroblast function can limit important stromal tumor-suppressive mechanisms, while promoting a switch to a cancer-supporting CAF phenotype.

Cancer-Associated Fibroblasts in Pancreatic Ductal Adenocarcinoma: An Update on Heterogeneity and Therapeutic Targeting

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related morbidity and mortality in the western world, with limited therapeutic strategies and dismal long-term survival. Cancer-associated fibroblasts (CAFs) are key components of the pancreatic tumor microenvironment, maintaining the extracellular matrix, while also being involved in intricate crosstalk with cancer cells and infiltrating immunocytes. Therefore, they are potential targets for developing therapeutic strategies against PDAC. However, recent studies have demonstrated significant heterogeneity in CAFs with respect to their origins, spatial distribution, and functional phenotypes within the PDAC tumor microenvironment. Therefore, it is imperative to understand and delineate this heterogeneity prior to targeting CAFs for PDAC therapy.

Tumor Microenvironment Features and Chemoresistance in Pancreatic Ductal Adenocarcinoma: Insights into Targeting Physicochemical Barriers and Metabolism as Therapeutic Approaches

Currently, the median overall survival of PDAC patients rarely exceeds 1 year and has an overall 5-year survival rate of about 9%. These numbers are anticipated to worsen in the future due to the lack of understanding of the factors involved in its strong chemoresistance. Chemotherapy remains the only treatment option for most PDAC patients; however, the available therapeutic strategies are insufficient. The factors involved in chemoresistance include the development of a desmoplastic stroma which reprograms cellular metabolism, and both contribute to an impaired response to therapy. PDAC stroma is composed of immune cells, endothelial cells, and cancer-associated fibroblasts embedded in a prominent, dense extracellular matrix associated with areas of hypoxia and acidic extracellular pH. While multiple gene mutations are involved in PDAC initiation, this desmoplastic stroma plays an important role in driving progression, metastasis, and chemoresistance. Elucidating the mechanisms underlying PDAC resistance are a prerequisite for designing novel approaches to increase patient survival. In this review, we provide an overview of the stromal features and how they contribute to the chemoresistance in PDAC treatment. By highlighting new paradigms in the role of the stromal compartment in PDAC therapy, we hope to stimulate new concepts aimed at improving patient outcomes.

Rho-Kinase as a Target for Cancer Therapy and Its Immunotherapeutic Potential

Cancer immunotherapy is fast rising as a prominent new pillar of cancer treatment, harnessing the immune system to fight against numerous types of cancer. Rho-kinase (ROCK) pathway is involved in diverse cellular activities, and is therefore the target of interest in various diseases at the cellular level including cancer. Indeed, ROCK is well-known for its involvement in the tumor cell and tumor microenvironment, especially in its ability to enhance tumor cell progression, migration, metastasis, and extracellular matrix remodeling. Importantly, ROCK is also considered to be a novel and effective modulator of immune cells, although further studies are needed. In this review article, we describe the various activities of ROCK and its potential to be utilized in cancer treatment, particularly in cancer immunotherapy, by shining a light on its activities in the immune system.

The PDAC Extracellular Matrix: A Review of the ECM Protein Composition, Tumor Cell Interaction, and Therapeutic Strategies

Pancreatic ductal adenocarcinoma (PDAC) is notorious for a dense fibrotic stroma that is interlaced with a collagen-based extracellular matrix (ECM) that plays an important role in tumor biology. Traditionally thought to only provide a physical barrier from host responses and systemic chemotherapy, new studies have demonstrated that the ECM maintains biomechanical and biochemical properties of the tumor microenvironment (TME) and restrains tumor growth. Recent studies have shown that the ECM augments tumor stiffness, interstitial fluid pressure, cell-to-cell junctions, and microvascularity using a mix of biomechanical and biochemical signals to influence tumor fate for better or worse. In addition, PDAC tumors have been shown to use ECM-derived peptide fragments as a nutrient source in nutrient-poor conditions. While collagens are the most abundant proteins found in the ECM, several studies have identified growth factors, integrins, glycoproteins, and proteoglycans in the ECM. This review focuses on the dichotomous nature of the PDAC ECM, the types of collagens and other proteins found in the ECM, and therapeutic strategies targeting the PDAC ECM.

Molecular mechanisms of pancreatic myofibroblast activation in chronic pancreatitis and pancreatic ductal adenocarcinoma

Pancreatic fibrosis (PF) is an essential component of the pathobiology of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC). Activated pancreatic myofibroblasts (PMFs) are crucial for the deposition of the extracellular matrix, and fibrotic reaction in response to sustained signaling. Consequently, understanding of the molecular mechanisms of PMF activation is not only critical for understanding CP and PDAC biology but is also a fertile area of research for the development of novel therapeutic strategies for pancreatic pathologies. This review analyzes the key signaling events that drive PMF activation including, initiating signals from transforming growth factor-β1, platelet derived growth factor, as well as other microenvironmental cues, like hypoxia and extracellular matrix rigidity. Further, we discussed the intracellular signal events contributing to PMF activation, and crosstalk with different components of tumor microenvironment. Additionally, association of epidemiologically established risk factors for CP and PDAC, like alcohol intake, tobacco exposure, and metabolic factors with PMF activation, is discussed to comprehend the role of lifestyle factors on pancreatic pathologies. Overall, this analysis provides insight into the biology of PMF activation and highlights salient features of this process, which offer promising therapeutic targets.

Apoptosis in the Pancreatic Cancer Tumor Microenvironment-The Double-Edged Sword of Cancer-Associated Fibroblasts

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis. This is attributed to the disease already being advanced at presentation and having a particularly aggressive tumor biology. The PDAC tumor microenvironment (TME) is characterized by a dense desmoplastic stroma, dominated by cancer-associated fibroblasts (CAF), extracellular matrix (ECM) and immune cells displaying immunosuppressive phenotypes. Due to the advanced stage at diagnosis, the depletion of immune effector cells and lack of actionable genomic targets, the standard treatment is still apoptosis-inducing regimens such as chemotherapy. Paradoxically, it has emerged that the direct induction of apoptosis of cancer cells may fuel oncogenic processes in the TME, including education of CAF and immune cells towards pro-tumorigenic phenotypes. The direct effect of cytotoxic therapies on CAF may also enhance tumorigenesis. With the awareness that CAF are the predominant cell type in PDAC driving tumorigenesis with various tumor supportive functions, efforts have been made to try to target them. However, efforts to target CAF have, to date, shown disappointing results in clinical trials. With the help of sophisticated single cell analyses it is now appreciated that CAF in PDAC are a heterogenous population with both tumor supportive and tumor suppressive functions. Hence, there remains a debate whether targeting CAF in PDAC is a valid therapeutic strategy. In this review we discuss how cytotoxic therapies and the induction of apoptosis in PDAC fuels oncogenesis by the education of surrounding stromal cells, with a particular focus on the potential pro-tumorigenic outcomes arising from targeting CAF. In addition, we explore therapeutic avenues to potentially avoid the oncogenic effects of apoptosis in PDAC CAF.

Interactions between Cancer-Associated Fibroblasts and T Cells in the Pancreatic Tumor Microenvironment and the Role of Chemokines

Less than 10% of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) survive 5 years or more, making it one of the most fatal cancers. Accumulation of T cells in pancreatic tumors is associated with better prognosis, but immunotherapies to enhance the anti-tumor activity of infiltrating T cells are failing in this devastating disease. Pancreatic tumors are characterized by a desmoplastic stroma, which mainly consists of activated cancer-associated fibroblasts (CAFs). Pancreatic CAFs have emerged as important regulators of the tumor microenvironment by contributing to immune evasion through the release of chemokines, cytokines, and growth factors, which alters T-cell migration, differentiation and cytotoxic activity. However, recent discoveries have also revealed that subsets of CAFs with diverse functions can either restrain or promote tumor progression. Here, we discuss our current knowledge about the interactions between CAFs and T cells in PDAC and summarize different therapy strategies targeting the CAF-T cell axis with focus on CAF-derived soluble immunosuppressive factors and chemokines. Identifying the functions of different CAF subsets and understanding their roles in T-cell trafficking within the tumor may be fundamental for the development of an effective combinational treatment for PDAC.

Microvesicles - promising tiny players' of cancer stem cells targeted liver cancer treatments: The interesting interactions and therapeutic aspects

Liver cancer is one of the most malignant cancers worldwide with poor prognosis. Intracellular mediators like microvesicles (MVs) and cancer stem cells (CSCs) are considered as potential candidates in liver cancer progression. CSCs receive stimuli from the tumor microenvironment to initiate tumor formation in which it's secreted MVs play a noteworthy role. The phenotypic conversion of tumor cells during epithelial-to-mesenchymal transition (EMT) is a key step in tumor invasion and metastasis which indicates that the diverse cell populations within the primary tumor are in a dynamic balance and can be regulated by cell to cell communication via secreted microvesicles. Thus, in this review, we aim to highlight the evidences that suggest CSCs are crucial for liver cancer development where the microvesicles plays an important part in the maintenance of its stemness properties. In addition, we summarize the existing evidences that support the concept of microvesicles, the tiny particles have a big role behind the rare immortal CSCs which controls the tumor initiation, propagation and metastasis in liver cancer. Identifying interactions between CSCs and microvesicles may offer new insights into precise anti-cancer therapies in the future.

Long non-coding RNAs regulate the hallmarks of cancer in HPV-induced malignancies

High-risk human papillomavirus (HPV) is the most frequent sexually transmitted agent worldwide and is responsible for approximately 5% of human cancers. Identifying novel biomarkers and therapeutic targets for these malignancies requires a deeper understanding of the mechanisms involved in the progression of HPV-induced cancers. Long non-coding RNAs (lncRNAs) are crucial in the regulation of biological processes. Importantly, these molecules are key players in the progression of multiple malignancies and are able to regulate the development of the different hallmarks of cancer. This review highlights the action of lncRNAs in the regulation of cellular processes leading to the typical hallmarks of cancer. The regulation of lncRNAs by HPV oncogenes, their targets and also their mechanisms of action are also discussed, in the context of HPV-induced malignancies. Overall, accumulating data indicates that lncRNAs may have a significant potential to become useful tools for clinical practice as disease biomarkers or therapy targets.

The Role of Stellate Cells in Pancreatic Ductal Adenocarcinoma: Targeting Perspectives

Pancreatic ductal adenocarcinoma (PDAC) is a gastrointestinal malignancy with a dismal clinical outcome. Accumulating evidence suggests that activated pancreatic stellate cells (PSCs), the major producers of extracellular matrix (ECM), drive the severe stromal/desmoplastic reaction in PDAC. Furthermore, the crosstalk among PSCs, pancreatic cancer cells (PCCs) as well as other stroma cells can establish a growth-supportive tumor microenvironment (TME) of PDAC, thereby enhancing tumor growth, metastasis, and chemoresistance via various pathways. Recently, targeting stroma has emerged as a promising strategy for PDAC therapy, and several novel strategies have been proposed. The aim of our study is to give a profound review of the role of PSCs in PDAC progression and recent advances in stroma-targeting strategies.

Role of HAND2-AS1 in human tumors

Long noncoding RNAs (lncRNAs) are molecules more than 200 nucleotides in length. They play roles in various cells, mainly regulating cell growth, differentiation, and apoptosis. They also participate in the pathogenesis of many diseases. In fact, several studies have shown that lncRNAs function as cancer or tumor suppressor genes and play important roles in the occurrence and development of cancer in humans. New evidence has shown that lncRNA heart and neural crest derivatives expressed 2-antisense RNA 1 (lncRNA HAND2-AS1) hinders the occurrence and development of various tumors. Overexpression of HAND2-AS1 was found to be significantly related to the clinical and pathological characteristics of cancer patients, as well as the regulation of cell proliferation, apoptosis, invasion, metastasis, and energy metabolism through several possible mechanisms. Therefore, HAND2-AS1 may be a promising tumor biomarker and therapeutic target. Here, we review the biological functions, mechanisms, and potential clinical significance of HAND2-AS1 in numerous human tumors.

Should we keep rocking? Portraits from targeting Rho kinases in cancer

Cancer targeted therapy, either alone or in combination with conventional chemotherapy, could allow the survival of patients with neoplasms currently considered incurable. In recent years, the dysregulation of the Rho-associated coiled-coil kinases (ROCK1 and ROCK2) has been associated with increased metastasis and poorer patient survival in several tumor types, and due to their essential roles in regulating the cytoskeleton, have gained popularity and progressively been researched as targets for the development of novel anti-cancer drugs. Nevertheless, in a pediatric scenario, the influence of both isoforms on prognosis remains a controversial issue. In this review, we summarize the functions of ROCKs, compile their roles in human cancer and their value as prognostic factors in both, adult and pediatric cancer. Moreover, we provide the up-to-date advances on their pharmacological inhibition in pre-clinical models and clinical trials. Alternatively, we highlight and discuss detrimental effects of ROCK inhibition provoked not only by the action on off-targets, but most importantly, by pro-survival effects on cancer stem cells, dormant cells, and circulating tumor cells, along with cell-context or microenvironment-dependent contradictory responses. Together these drawbacks represent a risk for cancer cell dissemination and metastasis after anti-ROCK intervention, a caveat that should concern scientists and clinicians.

Shedding new light on RhoA signalling as a drug target in vivo using a novel RhoA-FRET biosensor mouse

The small GTPase RhoA is a master regulator of signalling in cell-extracellular matrix interactions. RhoA signalling is critical to many cellular processes including migration, mechanotransduction, and is often disrupted in carcinogenesis. Investigating RhoA activity in a native tissue environment is challenging using conventional biochemical methods; we therefore developed a RhoA-FRET biosensor mouse, employing the adaptable nature of intravital imaging to a variety of settings. Mechanotransduction was explored in the context of osteocyte processes embedded in the calvaria responding in a directional manner to compression stress. Further, the migration of neutrophils was examined during in vivo "chemotaxis" in wound response. RhoA activity was tightly regulated during tissue remodelling in mammary gestation, as well as during mammary and pancreatic carcinogenesis. Finally, pharmacological inhibition of RhoA was temporally resolved by the use of optical imaging windows in fully developed pancreatic and mammary tumours in vivo. The RhoA-FRET mouse therefore constitutes a powerful tool to facilitate development of new inhibitors targeting the RhoA signalling axis.

An NMF-Based Methodology for Selecting Biomarkers in the Landscape of Genes of Heterogeneous Cancer-Associated Fibroblast Populations

The rapid development of high-performance technologies has greatly promoted studies of molecular oncology producing large amounts of data. Even if these data are publicly available, they need to be processed and studied to extract information useful to better understand mechanisms of pathogenesis of complex diseases, such as tumors. In this article, we illustrated a procedure for mining biologically meaningful biomarkers from microarray datasets of different tumor histotypes. The proposed methodology allows to automatically identify a subset of potentially informative genes from microarray data matrices, which differs either in the number of rows (genes) and of columns (patients). The methodology integrates nonnegative matrix factorization method, a functional enrichment analysis web tool with a properly designed gene extraction procedure to allow the analysis of omics input data with different row size. The proposed methodology has been used to mine microarray of solid tumors of different embryonic origin to verify the presence of common genes characterizing the heterogeneity of cancer-associated fibroblasts. These automatically extracted biomarkers could be used to suggest appropriate therapies to inactivate the state of active fibroblasts, thus avoiding their action on tumor progression.

Natural products and phytochemical nanoformulations targeting mitochondria in oncotherapy: an updated review on resveratrol

Mitochondria are intracellular organelles with two distinct membranes, known as an outer mitochondrial membrane and inner cell membrane. Originally, mitochondria have been derived from bacteria. The main function of mitochondria is the production of ATP. However, this important organelle indirectly protects cells by consuming oxygen in the route of energy generation. It has been found that mitochondria are actively involved in the induction of the intrinsic pathways of apoptosis. So, there have been efforts to sustain mitochondrial homeostasis and inhibit its dysfunction. Notably, due to the potential role of mitochondria in the stimulation of apoptosis, this organelle is a promising target in cancer therapy. Resveratrol is a non-flavonoid polyphenol that exhibits significant pharmacological effects such as antioxidant, anti-diabetic, anti-inflammatory and anti-tumor. The anti-tumor activity of resveratrol may be a consequence of its effect on mitochondria. Multiple studies have investigated the relationship between resveratrol and mitochondria, and it has been demonstrated that resveratrol is able to significantly enhance the concentration of reactive oxygen species, leading to the mitochondrial dysfunction and consequently, apoptosis induction. A number of signaling pathways such as sirtuin and NF-κB may contribute to the mitochondrial-mediated apoptosis by resveratrol. Besides, resveratrol shifts cellular metabolism from glycolysis into mitochondrial respiration to induce cellular death in cancer cells. In the present review, we discuss the possible interactions between resveratrol and mitochondria, and its potential application in cancer therapy.

Desmoplasia and Biophysics in Pancreatic Ductal Adenocarcinoma: Can We Learn From Breast Cancer?

Pancreatic ductal adenocarcinoma (PDAC) treatments have historically focused on targeting tumor cells directly. However, in pancreatic masses, the stroma encasing the malignant epithelial cells constitutes up to 80% to 90% of the tumor bulk. This extracellular matrix, which was previously neglected when designing cancer therapies, is now considered fundamental for tumor progression and drug delivery. Desmoplastic tissue is extensively cross-linked, resulting in tremendous tensile strength. This key pathological feature is procarcinogenic, linking PDAC and breast cancer (BC). Physical forces exerted onto cellular surfaces are detected intracellularly and transduced via biochemical messengers in a process called mechanotransduction. Mechanotransduction and tensional homeostasis are linked, with an integral role in influencing tumor growth, metastasis, and interactions with the immune system. It is essential to enhance our knowledge of these integral elements of parenchymal tumors. We aim to review the topic, with a special emphasis on desmoplastic processes and their importance in pancreatic and BC development and treatments, mindful that innovative diagnostic and therapeutic strategies cannot focus on biochemical pathways alone. We then focus on common therapeutic targets identified in both PDAC and BC models and/or patients, aiming to understand these treatments and draw similarities between the two tumors.

Rho-ROCK Signaling in Normal Physiology and as a Key Player in Shaping the Tumor Microenvironment

The Rho-ROCK signaling network has a range of specialized functions of key biological importance, including control of essential developmental processes such as morphogenesis and physiological processes including homeostasis, immunity, and wound healing. Deregulation of Rho-ROCK signaling actively contributes to multiple pathological conditions, and plays a major role in cancer development and progression. This dynamic network is critical in modulating the intricate communication between tumor cells, surrounding diverse stromal cells and the matrix, shaping the ever-changing microenvironment of aggressive tumors. In this chapter, we overview the complex regulation of the Rho-ROCK signaling axis, its role in health and disease, and analyze progress made with key approaches targeting the Rho-ROCK pathway for therapeutic benefit. Finally, we conclude by outlining likely future trends and key questions in the field of Rho-ROCK research, in particular surrounding Rho-ROCK signaling within the tumor microenvironment.

Discoidin Domain Receptors, DDR1b and DDR2, Promote Tumour Growth within Collagen but DDR1b Suppresses Experimental Lung Metastasis in HT1080 Xenografts

The Discoidin Domain Receptors (DDRs) constitute a unique set of receptor tyrosine kinases that signal in response to collagen. Using an inducible expression system in human HT1080 fibrosarcoma cells, we investigated the role of DDR1b and DDR2 on primary tumour growth and experimental lung metastases. Neither DDR1b nor DDR2 expression altered tumour growth at the primary site. However, implantation of DDR1b- or DDR2-expressing HT1080 cells with collagen I significantly accelerated tumour growth rate, an effect that could not be observed with collagen I in the absence of DDR induction. Interestingly, DDR1b, but not DDR2, completely hindered the ability of HT1080 cells to form lung colonies after intravenous inoculation, suggesting a differential role for DDR1b in primary tumour growth and lung colonization. Analyses of tumour extracts revealed specific alterations in Hippo pathway core components, as a function of DDR and collagen expression, that were associated with stimulation of tumour growth by DDRs and collagen I. Collectively, these findings identified divergent effects of DDRs on primary tumour growth and experimental lung metastasis in the HT1080 xenograft model and highlight the critical role of fibrillar collagen and DDRs in supporting the growth of tumours thriving within a collagen-rich stroma.

MicroRNA-582-5p Reduces Propofol-induced Apoptosis in Developing Neurons by Targeting ROCK1

BACKGROUND

Propofol is an intravenous drug commonly used in anesthesia procedures and intensive care in children. However, it also has neurotoxic effects on children. MicroRNA plays an important role in neurological diseases and neurotoxicity.

METHODS

In this study, primary rat hippocampal neurons were used to investigate the role of miR- 582-5p in propofol-induced neurotoxicity. Cell viability was monitored by 3-(4,5-dimethylthiazolyl)- 2,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while the expression of proteins was monitored by real-time quantitation polymerase chain reaction (RT-qPCR) and western blot. TargetScan and double luciferase report assay were used to predict the targeting relationship between miR-582-5p and Rho-associated serine-threonine protein kinase 1 (ROCK1).

RESULTS

In the present study, the viability of neurons and the expression of miR-582-5p were decreased in a time-dependent manner after propofol treatment. Besides, miR-582-5p overexpression significantly reduced the toxicity of propofol on neuron cells but had no significant effect on normal nerve cells. In addition, miR-582-5p overexpression significantly reversed the expression of apoptosis-related proteins (cleaved caspase 3 and cleaved caspase 9) induced by propofol but had no significant effect in normal nerve cells. TargetScan and Dual-luciferase report assay revealed that ROCK1 was a targeted regulatory gene for miR-582-5p, and propofol treatment up-regulated ROCK1 expression by inhibiting miR-582-5p expression. Notably, miR-582-5p overexpression significantly increased cell viability, while ROCK1 overexpression reversed the effect of miR-582- 5p.

CONCLUSION

Taken together, these findings suggest that miR-582-5p alleviated propofol-induced apoptosis of newborn rat neurons by inhibiting ROCK1.

Extracellular Matrix in the Tumor Microenvironment and Its Impact on Cancer Therapy

Solid tumors are complex organ-like structures that consist not only of tumor cells but also of vasculature, extracellular matrix (ECM), stromal, and immune cells. Often, this tumor microenvironment (TME) comprises the larger part of the overall tumor mass. Like the other components of the TME, the ECM in solid tumors differs significantly from that in normal organs. Intratumoral signaling, transport mechanisms, metabolisms, oxygenation, and immunogenicity are strongly affected if not controlled by the ECM. Exerting this regulatory control, the ECM does not only influence malignancy and growth of the tumor but also its response toward therapy. Understanding the particularities of the ECM in solid tumor is necessary to develop approaches to interfere with its negative effect. In this review, we will also highlight the current understanding of the physical, cellular, and molecular mechanisms by which the pathological tumor ECM affects the efficiency of radio-, chemo-, and immunotherapy. Finally, we will discuss the various strategies to target and modify the tumor ECM and how they could be utilized to improve response to therapy.

Ultra-Sensitive Automated Profiling of EpCAM Expression on Tumor-Derived Extracellular Vesicles

Extracellular vesicles (EVs) are abundant in most biological fluids and considered promising biomarker candidates, but the development of EV biomarker assays is hindered, in part, by their requirement for prior EV purification and the lack of standardized and reproducible EV isolation methods. We now describe a far-field nanoplasmon-enhanced scattering (FF-nPES) assay for the isolation-free characterization of EVs present in small volumes of serum (< 5 µl). In this approach, EVs are captured with a cancer-selective antibody, hybridized with gold nanorods conjugated with an antibody to the EV surface protein CD9, and quantified by their ability to scatter light when analyzed using a fully automated dark-field microscope system. Our results indicate that FF-nPES performs similarly to EV ELISA, when analyzing EV surface expression of epithelial cell adhesion molecule (EpCAM), which has clinical significant as a cancer biomarker. Proof-of-concept FF-nPES data indicate that it can directly analyze EV EpCAM expression from serum samples to distinguish early stage pancreatic ductal adenocarcinoma patients from healthy subjects, detect the development of early stage tumors in a mouse model of spontaneous pancreatic cancer, and monitor tumor growth in patient derived xenograft mouse models of pancreatic cancer. FF-nPES thus appears to exhibit strong potential for the direct analysis of EV membrane biomarkers for disease diagnosis and treatment monitoring.

CAF Subpopulations: A New Reservoir of Stromal Targets in Pancreatic Cancer

Cancer-associated fibroblasts (CAFs) are one of the most significant components in the tumour microenvironment (TME), where they can perform several protumourigenic functions. Several studies have recently reported that CAFs are more heterogenous and plastic than was previously thought. As such, there has been a shift in the field to study CAF subpopulations and the emergent functions of these subsets in tumourigenesis. In this review, we explore how different aspects of CAF heterogeneity are defined and how these manifest in multiple cancers, with a focus on pancreatic ductal adenocarcinoma (PDAC). We also discuss therapeutic approaches to selectively target protumourigenic CAF functions, while avoiding normal fibroblasts, providing insight into the future of stromal targeting for the treatment of PDAC and other solid tumours.